The ladder style construction of rucksack harness adjustment systems is well known. The best known of these systems is the PARALUX (Trade Mark) suspension system. Many modifications and variations of this system are currently available on the high grade rucksack and climbing equipment market. The PARALUX(.TM.) system is known for its ruggedness, durability and stability in use. Some modifications of this system have similar performance to the PARALUX(.TM.) system but usually comprise expensive alternative components.
In the PARALUX(.TM.) suspension system a plurality of transverse webs are sewn in ladder-like fashion to the back wall of the rucksack. The shoulder straps terminate in a strap which is threaded through a selected one of the webs depending on the desired location of the shoulder straps. The strap is then threaded through a buckle and tightened, threaded under the next highest ladder web, through a web on the shoulder harness, and then threaded through a further ladder web.
The loose end of the strap is pushed down behind the ladder configuration. Finally, a top stabilizer web is threaded through buckles at the top of the ladder to stabilize the connection.
A known disadvantage of the ladder type adjustment system is its relative complexity. A rucksack owner may easily forget how to adjust the system to account for different loads or different users. Additionally, at points of sale, adjustment of a rucksack to fit a number of customers is time consuming and off-putting to both the customer and retailer.
As a result of the ladder configuration of the restraining bands, adjustment of the harness or harness yoke with respect to the rucksack may only be facilitated at a small number of adjustment positions along the ladder structure, usually one position approximately every 5 cm. Each rung of the ladder comprises a band of 2.5 cm wide strap with a similar spacing between each strap. Consequently, for a 30 cm adjustment ladder only six adjustment positions are available.
German Gebrauchsmuster No. G 92 11 744.9 discloses a rucksack comprising a backpack having at an upper region of the back wall two carrier straps which are height-adjustably secured to the back wall. A plurality of transverse loops or webs are stitched to the back wall of the backpack in spaced apart and ladder-like fashion. The shoulder straps are joined together by a harness yoke, and a plate attached to the yoke is inserted behind a selected loop and is locked in position by means of a snap fastener. The invention is concerned with the provision of a guide for the purpose of facilitating the positive guidance of the plate through the loops. The guide is in the form of a band of textile material which extends continuously over the height of the loops.
German Patent Application No. DE 3045881 discloses a height-adjustable system for attaching a carrying harness to a rucksack in which a number of transverse bands or webs are sewn to the rear wall of the rucksack to form a ladder-like configuration similar to the PARALUX(.TM.) system described above. The transverse bands are sewn to the rear wall of the rucksack by means of stitches which extend in a v-shape, to provide for varying shoulder widths.
The arrangements described in the above German Gebrauchsmuster and patent application suffer from the same disadvantages as described above in relation to the PARALUX.TM.system, namely that adjustment may be complicated for the user, and a fine adjustment is not readily obtainable.
Mechanical means are known for adjusting the height of the shoulder harness on rucksacks, typically in which the yoke connecting the shoulder harness slides in vertically arranged runners or tracks on the back wall of the rucksack, and is locked in place by a locking system. Known mechanical systems include the TORSO TRAC.TM. suspension system (U.S. Pat. No. 4,860,936), and the systems described, for example, in European Patent 0,173,024 and German Gebrauchsmuster No. G 87 16 869.3. While these mechanical systems offer a quick and easy method of height adjustment they are expensive to manufacture. Also there is a tendency for the yoke to slip, and the locking system can cause problems.
FR, A, 2 695 016 (LAFUMA) is a document published prior to the international filing date but later than the priority date claimed. This document discloses a rucksack harness having a pair of shoulder carrier straps joined together at one end at a harness yoke, and yoke engagement means attached to the rear wall of the rucksack. The yoke engagement means comprises a plurality of horizontal slats. A strap attached to the yoke is passed under selected slats, threaded upwardly behind the slats, to emerge adjacent the top of the slats, from where it is folded over, and attached by quick fastening means (e.g. VELCRO.TM. to the yoke. The horizontal slats are spaced apart at regular intervals in a vertical direction, and do not provide for fine adjustment.